Jearitm atkins



.T0 ALL WHOM I'I MAY CONCERN:

@einen tete etwt @ffice Liegi-s faim No. 75,827, dared Mwah 24', 186s.

IMPROVEMENT IN GALIIERS.

:tite rigebule miem-t in in iigrs'e iritcrs atnii mit uniting part ettigt Ytime;

Be it known that I, JERUM ATKINS, of Washington, in the District ol'Columbia., have invented anew .jmd useful Improvement in Calipers; und Ihereby declare the following to be a full and exact description ol' thesame, reference being had to the drawings that accompany and form o.part of these specifications.

Themature of my invention consists in the use of e combined screwand'riv'et for fastening and clamping the calipers in any desiredposition, whereby a. very nent, chenp,va,n 1 llcientjnstrnment isobtained.

' Figure lis a. sidp viewof the calipers complete.

-Figure 2, a. section at right ungles'vwith iig. 1, taken `on the pinneof the'centre oi' thc screw. Figure 3 shows the screw as it is formedbefore riveting, with the nut G attached.

Figure 4, a. washer, to be placed between theA nut and the upper .leg ofthe calipers. I construct my calipers in the usuat'forin, except in Ythemanner ol fastening mdclnmping the samewhich is eiecte'd by Amenus ofthe combined rivet :mil screw A. This.rivet is square between the linesB and C, iig. 3, and enlarged at D. This enlargement aotsl'cnnjointlywith the lower heed, E, in fastening the two legs of the caliperstogether. A washer` F, is placed around the screw, over the upper leg ofthe calipers, to receive thc pressure ofthe nut-Gr. Thot portion oi thescrew contained within the washer AF is squnre, (the hole in' the washerbeing made' to t) to prevent the latter from turning ronnflas the screwis tightened for clamping the calipers, and holding-them firmly in anyposition which miybe desirable. The under side of the wzisher F isslightly concave, so'thetV only its outel edge shnll beu-r upon thelupper leg of thel calipers, nml does not rest upon thc shoulder upon thescrew just beneath it when the nut is tightened. Y

The advantage claimed for this invention is as follows: The rivet een betightened to any degree that may be desirable, leaving the calipersseth-nt they may be easily set-tn any-sized work. Then, when they `nreonce set, the nut can, be tightened upfor clamping the-calipers andholding them firmly, so that there may be no danger of their beingaccidentally changed while being used.

Having thus described my invention,`I desire to statte ahnt I 'donutclaim as new the fastening of calipers by means .cfa rivet, neither do Iclaim ns new clampinglthe some by means of a. sci-ew and nut.

What I claim as my invention, and desire to secureby Letters Patent, isI The within-described arrangement for fastening and claniping calipers.nfi the combined rivet and screw. A, with its nut G- and washer E,substantially :is described.

In testimony whereof, I have signed my name to this specicution in thepresence of two subscribing witnesses.

JEARUM ATKINS,

Witnessesf DANIEL D. ROBINSON', DAVID M. VAN NARA sreAN.

